Following your suggestions I've made my best to incorporate the speech sounds (and a way to disable them in the game menu, of course). This is the best I could do and they are eating nearly all my free memory.

They are not as fun and great as I'd imagined... Any comments or suggestions are welcome. And no: it is not easy to sync the mouth animation to the sounds...

Maybe there should just be a sound effect at the beginning of the sentence, for each character? Sort of a short, pulsed sound with different pitches for each character - only so we can tell the beginning of a new sentence, by a new character, and not necessarily hear it for the entire duration?

Well, unless I need the space and there is no way to get it through some code revising, this does not need to be dropped. Specially when the player can deactivate it.

The thing is that I need to tweak more code in order to produce the same effect in other cases (not only on the Talk command associated to a character, I mean, as I may want to simulate speech heard from radio or coming out of a robot). This probably means another script command. I'll see if I have room for that too.

I think it sounds weird mostly because it's the same sound for both characters.
My idea was to have different pitch for the various characters, like for the woman here have her speak one octave higher.

I guess the thing is if it is good enough as to be kept in a final version or not. Or if it is good enough as to not include other features because of it...

I will try to tweak a few things to make it slightly better. I might find a hack to make small alterations to the sounds so they seem different for each character, but I am not sure if I'll be able to do something that really works. For instance, I have no way to tell if a character is a woman to make the pitch higher, and all I could do is a hack which won't be general at all.

ha ha ha good point Dbug. That is exactly what I am trying to do... but that won't decide between man/woman... just a base for the note variations which may coincide or not

One thing. I just added pauses in the talk animation whenever there is a pause in the sfx (which occur, in turn, when there is a space or a full stop) and that changes things a lot! The sound sounds the same, of course, but visually it works much much better.

Now, in order to add the color thing, I need to find some free memory. I have 3 bytes left!!! Moving some tables to normal memory (the engine is in overlay ram) could be done, but I have only 23 bytes left there... Okay, gimme some time to find out where to scratch some bytes...

I think you should try the idea of only using a small, short sound at the beginning of each sentence, to differentiate when one character starts talking and the other starts listening. This works pretty well - especially if the tones are different. All thats needed is there to be a different tone - it doesn't matter if they match the characters' sex - just that there is a small beep/boop that is unique to the character.

I have tweaked the whole system, increased the volume, added different base pitch as suggested by Dbug and synchronized (a bit) the lips with the sounds. It looks much better, in my opinion, but still uncertain about it reaching the final version.

It can, of course, be deactivated with the menu (without affecting the rest of sounds) and uses the player's setup for game sound volume.

It was fun, entertaining and I learnt a lot. I even discovered a couple of small bugs while testing this, but the benefits are not as I expected. Probably with samples or more control over the sound chip, nice things could be done, but this it not the case.... I will deactivate the #define. Fortunately that brings me about 150 bytes free for other stuff.